/* roulang page: index */
:root {
      --primary-deep: #0A0F1E;
      --accent-green: #00F0A8;
      --accent-red: #FF4D6D;
      --neutral-light: #F5F6FA;
      --neutral-card: #1B2234;
      --neutral-muted: #8E94A4;
      --white: #ffffff;
      --shadow-card: 0 12px 32px rgba(0, 0, 0, 0.35);
      --shadow-hover: 0 20px 40px rgba(0, 240, 168, 0.15);
      --radius-card: 20px;
      --radius-btn: 10px;
      --radius-input: 8px;
      --transition-smooth: all 0.25s ease;
      --font-heading: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
      --font-number: 'Rajdhani', 'Inter', sans-serif;
      --font-body: 'Inter', 'PingFang SC', 'Microsoft YaHei', system-ui, -apple-system, sans-serif;
    }

    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }

    html {
      scroll-behavior: smooth;
      background-color: var(--primary-deep);
    }

    body {
      font-family: var(--font-body);
      background-color: var(--primary-deep);
      color: #E0E4EC;
      line-height: 1.6;
      font-size: 16px;
      -webkit-font-smoothing: antialiased;
      overflow-x: hidden;
    }

    img {
      max-width: 100%;
      height: auto;
      display: block;
    }

    a {
      text-decoration: none;
      color: inherit;
      transition: var(--transition-smooth);
    }

    button, .btn {
      cursor: pointer;
      font-family: var(--font-body);
      border: none;
      background: none;
      transition: var(--transition-smooth);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 0.5rem;
    }

    .container {
      max-width: 1280px;
      margin: 0 auto;
      padding: 0 32px;
    }

    /* 导航系统 */
    .site-header {
      position: fixed;
      top: 0;
      left: 0;
      width: 100%;
      z-index: 1000;
      background: transparent;
      transition: background 0.3s ease, backdrop-filter 0.3s ease;
    }

    .site-header.scrolled {
      background: rgba(10, 15, 30, 0.88);
      backdrop-filter: blur(20px);
      -webkit-backdrop-filter: blur(20px);
      box-shadow: 0 4px 20px rgba(0,0,0,0.3);
    }

    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      height: 80px;
    }

    .logo {
      font-family: var(--font-heading);
      font-weight: 700;
      font-size: 1.8rem;
      letter-spacing: 0.5px;
      color: var(--white);
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .logo span {
      color: var(--accent-green);
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 2.5rem;
    }

    .nav-links a {
      font-weight: 500;
      font-size: 1rem;
      color: #CCD0D9;
      position: relative;
    }
    .nav-links a:hover,
    .nav-links a:focus-visible {
      color: var(--accent-green);
    }

    .btn-primary {
      background: var(--accent-green);
      color: #0A0F1E;
      font-weight: 700;
      padding: 0.7rem 1.8rem;
      border-radius: var(--radius-btn);
      letter-spacing: 0.3px;
      box-shadow: 0 4px 14px rgba(0,240,168,0.3);
    }
    .btn-primary:hover {
      background: var(--accent-red);
      color: white;
      box-shadow: 0 8px 22px rgba(255,77,109,0.5);
      transform: translateY(-2px);
    }

    .hamburger {
      display: none;
      flex-direction: column;
      gap: 5px;
      background: transparent;
      border: none;
      width: 32px;
      height: 24px;
      justify-content: center;
    }
    .hamburger span {
      display: block;
      height: 2px;
      background: var(--white);
      border-radius: 2px;
      transition: 0.3s;
    }

    .mobile-menu {
      position: fixed;
      top: 0;
      right: 0;
      width: 75%;
      max-width: 320px;
      height: 100vh;
      background: #0F1525;
      backdrop-filter: blur(30px);
      transform: translateX(100%);
      transition: transform 0.3s ease;
      display: flex;
      flex-direction: column;
      padding: 2rem;
      z-index: 999;
    }
    .mobile-menu.active {
      transform: translateX(0);
    }
    .mobile-menu a {
      padding: 1rem 0;
      font-size: 1.2rem;
      border-bottom: 1px solid rgba(255,255,255,0.08);
      color: #ddd;
    }

    @media (max-width: 1024px) {
      .nav-links { display: none; }
      .hamburger { display: flex; }
    }

    /* 区块间距 */
    section {
      padding: 100px 0;
    }
    @media (max-width: 768px) {
      section { padding: 70px 0; }
      .container { padding: 0 20px; }
    }

    /* Hero */
    .hero {
      min-height: 100vh;
      display: flex;
      align-items: center;
      background: radial-gradient(circle at 30% 40%, rgba(0,240,168,0.12) 0%, transparent 50%), 
                  linear-gradient(180deg, #0A0F1E 0%, #0F172A 100%);
      position: relative;
      overflow: hidden;
    }
    .hero::before {
      content: "";
      position: absolute;
      width: 100%;
      height: 100%;
      background-image: repeating-linear-gradient(0deg, rgba(255,255,255,0.02) 0px, rgba(255,255,255,0.02) 1px, transparent 1px, transparent 40px);
      pointer-events: none;
    }
    .hero-content {
      position: relative;
      z-index: 2;
      display: flex;
      align-items: center;
      gap: 3rem;
    }
    .hero-text {
      flex: 1;
    }
    .hero h1 {
      font-family: var(--font-heading);
      font-size: clamp(2.8rem, 6vw, 4.5rem);
      font-weight: 800;
      color: white;
      line-height: 1.2;
      margin-bottom: 1.5rem;
    }
    .hero .sub {
      font-size: 1.2rem;
      color: #B0B8C5;
      margin-bottom: 2.5rem;
    }
    .hero-buttons {
      display: flex;
      gap: 1.2rem;
      flex-wrap: wrap;
    }
    .btn-outline {
      border: 1.5px solid var(--accent-green);
      color: var(--accent-green);
      background: transparent;
      padding: 0.7rem 2rem;
      border-radius: var(--radius-btn);
      font-weight: 600;
    }
    .btn-outline:hover {
      background: rgba(0,240,168,0.08);
      border-color: var(--accent-red);
      color: white;
    }
    .hero-image {
      flex: 1;
      display: flex;
      justify-content: center;
    }
    .hero-image img {
      border-radius: 24px;
      box-shadow: 0 25px 50px rgba(0,0,0,0.5);
      animation: float 5s ease-in-out infinite;
    }
    @keyframes float {
      0% { transform: translateY(0px); }
      50% { transform: translateY(-12px); }
      100% { transform: translateY(0px); }
    }
    @media (max-width: 900px) {
      .hero-content { flex-direction: column; text-align: center; }
      .hero-image img { max-width: 320px; }
      .hero-buttons { justify-content: center; }
    }

    /* 卡片通用 */
    .section-title {
      font-family: var(--font-heading);
      font-size: 2.4rem;
      font-weight: 700;
      margin-bottom: 1rem;
    }
    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 2rem;
    }
    .feature-card {
      background: var(--neutral-card);
      border-radius: var(--radius-card);
      padding: 2rem;
      border-left: 6px solid var(--accent-green);
      transition: var(--transition-smooth);
    }
    .feature-card:hover {
      transform: translateY(-6px);
      border-left-color: var(--accent-red);
      box-shadow: var(--shadow-hover);
    }
    @media (max-width: 768px) {
      .grid-3 { grid-template-columns: 1fr; }
    }

    .services-block {
      display: flex;
      gap: 3rem;
      align-items: center;
      margin-bottom: 4rem;
    }
    .services-block.reverse {
      flex-direction: row-reverse;
    }
    @media (max-width: 768px) {
      .services-block, .services-block.reverse { flex-direction: column; }
    }

    .process-steps {
      display: flex;
      justify-content: space-between;
      text-align: center;
    }
    .step-item {
      flex: 1;
      position: relative;
    }
    .step-number {
      font-family: var(--font-number);
      font-size: 3.5rem;
      font-weight: 700;
      color: var(--accent-green);
    }
    @media (max-width: 768px) {
      .process-steps { flex-direction: column; gap: 2rem; }
    }

    .stats-grid {
      display: grid;
      grid-template-columns: repeat(4,1fr);
      gap: 2rem;
    }
    .stat-card {
      background: #141B2B;
      padding: 2rem;
      border-radius: 16px;
      text-align: center;
    }
    .stat-number {
      font-family: var(--font-number);
      font-size: 3.2rem;
      font-weight: 700;
      color: var(--accent-red);
    }
    @media (max-width: 768px) {
      .stats-grid { grid-template-columns: 1fr 1fr; }
    }

    .faq-item {
      border-bottom: 1px solid rgba(255,255,255,0.08);
      padding: 1.2rem 0;
    }
    .faq-question {
      font-weight: 600;
      display: flex;
      justify-content: space-between;
      cursor: pointer;
    }
    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: 0.3s;
      color: #B0B8C5;
    }
    .faq-item.active .faq-answer {
      max-height: 200px;
      margin-top: 0.8rem;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1fr;
      gap: 2rem;
    }
    @media (max-width: 768px) {
      .footer-grid { grid-template-columns: 1fr; }
    }